The invention generally relates to location and tracking and more specifically to tracking position of assets using multiple local area networks.
A number of systems have been developed and deployed to locate and track the position of people and assets (collectively, “assets”) within local area environments such as office buildings, hospitals, shopping malls, and hotels, and/or industrial environments such as refineries, oil rigs, and manufacturing facilities. Existing systems are limited to accuracy of a few meters using an existing Wi-Fi or Bluetooth network. In addition, existing systems attempt to determine absolute position and are not able to determine proximity (e.g., two or more assets within a threshold distance from each other).
In order to save power, various system elements, such as zone tags and mobile tags, may go into sleep mode, and thus need to wake up at certain time instants specified by a server in order to determine position using the tags.
Therefore, there is a need for a way to synchronize the frame timing of zone tags and the mobile tags so that they may wake up at the time instants scheduled by a server.